perfection isn't really objective, for any flaw you can point out in a game I could argue it as a strength. take for example FFVII's infamous legoish character models, some would say that the game would be better with very realistic models. I think it's simplicity has a unique charm and that the juxtaposition of these primitive models against prerendered backgrounds gives the game it's own aesthetic that other games don't have. I would also say that realism in general isn't always desireable and that many older games being so blatantly limited gives them the aura of playing in someone elses dream rather than playing in another reality. realism vs an obvious creation is NOT a clear choice IMO, both have their merits and "executed to their fullest potential" is going to vary depending on your tastes, you can't please everyone so there can be no "perfect" game
also I don't think I could have an "ideal" game because I play different games for different reasons. obviously I get something different from playing majora's mask or MGS3 than I get out of playing brawl, I wouldn't say one is better than the other(er, yes I would, brawl is clearly worse than both of those games, but the KIND of game brawl is isn't inferior to the kind of games those are), they are simply separate entities which have their own unique criteria for excellence.